DTC Troubleshooting: B1226 (A-B2), B1226 (02)
DTC B1226 or DTC screen A-B2 or DTC indicator 02: A short in the in-car temperature sensor circuit
DTC Description
DTC
B1226 A short in the in-car temperature sensor circuit
  

1.
Problem verification:

Problem verification
?1.
Clear the DTC with the HDS.


?2.
Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

?3.
Do the Self-Diagnostic Function with the HDS or the climate control unit.

?4.
Check for DTCs.
DTC Description
DTC
B1226 A short in the in-car temperature sensor circuit
  

Is DTC B1226 or Error on the DTC screen A-B2 (climate control panel without display) or 02 (climate control panel with display) indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.?
2.
Shorted wire check (TR line):

Shorted wire check (TR line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Climate control unit connector A (32P)
In-car temperature sensor 2P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector A (32P): disconnected
In-car temperature sensor 2P connector: disconnected
Test point 1
Climate control unit connector A (32P) No. 27
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the TR wire.?
     
NO
     
     
     
The TR wire is not shorted. Go to step 3.
3.
Shorted wire check (TR line to SENSOR COM line):

Shorted wire check (TR line to SENSOR COM line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector A (32P): disconnected
In-car temperature sensor 2P connector: disconnected
Test point 1
Climate control unit connector A (32P) No. 12
Test point 2
Climate control unit connector A (32P) No. 27

Is there continuity?

     
YES
     
     
     
Repair a short in the TR wire to SENSOR COM wire.?
     
NO
     
     
     
The TR wire and SENSOR COM wire are OK. Go to step 4.
4.
In-car temperature sensor check:

In-car temperature sensor check
?1.
Test the in-car temperature sensor.

Is the in-car temperature sensor OK?

     
YES
     
     
     
     
NO